JPH11151814A - Ink-jet head and method for assembling ink-jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet head which indicates no difference in properties between nozzle lines and no proportional increase in the number of processing man-hours by the increase in the number of nozzle lines, and is capable of attaining miniaturization due to high density mounting. SOLUTION: On a base substrate 1 in which conductive parts 4a-4f and insulating parts 5a-5e are mounted alternately on the surface in the shape of a belt are arranged piezoelectric elements 2a-2c which are formed integrally for one line to be bonded so that both ends of the elements correspond to the individual conductive parts, respectively. The elements 2a-2c are notched to reach the substrate 1 to be separated into independent piezoelectric elements. Next, each element 2a-2c is covered with a print cable in which a corresponding conductive pattern 6 is formed to connect the pattern 6 electrically with each piezoelectric element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head used in an ink jet printer and a method of assembling the ink jet head, and more particularly to an ink jet head for discharging ink droplets by a piezoelectric element and a method of assembling the ink jet head.

[0002]

2. Description of the Related Art FIG. 3 is a perspective view for explaining a conventional ink jet head assembling method described in Japanese Patent Application Laid-Open No. 9-29979. As shown in FIG.
03, the flexible cable 102 and the piezoelectric element 104 are attached. In the flexible cable 102,
A land 121 serving as a common electrode and a land 122 serving as a positive electrode are provided. Further, the flexible cable 102 is provided with a hole 123. And
The flexible cable 102 is
And the piezoelectric element 104 are simultaneously processed. A groove 120 is formed by processing. Cut piezoelectric element 104
The land portions 121 and 122 corresponding to the respective portions
To form a piezoelectric element unit. Furthermore, when an inkjet head having a plurality of rows of piezoelectric elements is formed, a plurality of piezoelectric element units for one row are formed, and then these are individually bonded to a diaphragm.

[0003]

Since the conventional ink jet head is manufactured as described above, when an ink jet head having a plurality of piezoelectric element arrays is manufactured, the characteristics between the respective nozzle arrays may be affected by variations in bonding. There is a problem that a difference appears. As a result, in an ink jet head in which different colors correspond to a plurality of nozzle rows, a problem arises in that a desired print result cannot be obtained due to a characteristic difference between the nozzle rows. In addition, since the piezoelectric element units are bonded to the diaphragm in units of rows, the number of bonding steps is increased. Furthermore, since the process of individually processing the piezoelectric elements is performed in units of rows, there is a problem that the number of steps such as alignment for processing is increased.

Accordingly, an object of the present invention is to provide an ink jet head in which there is no characteristic difference between nozzle rows. It is another object of the present invention to provide an ink jet head in which the number of processing steps does not increase in proportion to an increase in the number of nozzle rows, and which can be mounted at high density and can be downsized.

[0005]

SUMMARY OF THE INVENTION An ink jet head according to the present invention is a piezoelectric element in which one row of heads is integrally formed on a base substrate having a plurality of conductive portions and insulating portions alternately provided on the surface in a strip shape. A printed cable in which a plurality of both ends are arranged and bonded so as to correspond to separate conductive portions, and each piezoelectric element is cut into individual piezoelectric elements while being cut into the base substrate, and then a corresponding conductive pattern is formed. And each of the individual piezoelectric elements and the conductive pattern are electrically connected to each other. Between the conductive portions on both sides of the piezoelectric element, 20 μm more than the width of the piezoelectric element
It may be formed to be wider than m. Further, the distance between the conductive portions on both sides of the piezoelectric element is 2
It may be formed to be narrower than 0 μm. As a printed cable on which a conductive pattern is formed, a flexible printed cable or TAB is used.

According to the method of assembling an ink jet head according to the present invention, both ends of a piezoelectric element in which one row of heads are integrally formed on a base substrate having a plurality of conductive portions and insulating portions alternately provided in a strip shape on the surface. A plurality of piezoelectric elements are arranged and bonded so as to correspond to different conductive portions, and each piezoelectric element is cut into individual piezoelectric elements while being cut to the base substrate, and a printed cable on which the corresponding conductive pattern is formed is covered on the base substrate, and The method includes the steps of electrically connecting the individual piezoelectric element and the conductive pattern.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view for explaining a configuration of an ink jet head according to the present invention.
FIG. 2 is an explanatory diagram for explaining the method of assembling the inkjet head. As shown in FIGS. 1A to 1C, the inkjet head has conductive portions 4a to 4c.
f and insulating portions 5a to 5e are alternately formed on the surface, the piezoelectric elements 2a to 2c each forming one row of piezoelectric element units, and the positions corresponding to the piezoelectric elements 2a to 2c. And a printed cable 3 having holes and a conductive pattern 6 printed thereon.

[0008] As shown in FIG.
a on both sides of the conductive elements 4a and 4b, on both sides of the piezoelectric element 2b on the conductive parts 4c and 4d, and on both sides of the piezoelectric element 2c on the conductive parts 4a and 4d.
Each of the piezoelectric elements 2a to 2c is attached to the base substrate 1 so as to correspond to e and 4f. Then, as shown in FIG. 2B, the piezoelectric elements 2a to 2c and each of the conductive portions 4a to 4c
f is electrically connected by solder 7 or the like. Thereafter, as shown in FIG. 2C, a groove indicated by reference numeral 8 is applied by a dicing saw, sand blast, wire saw, or the like, and the wafer is divided into individual piezoelectric element portions corresponding to the respective nozzles.

At this time, by cutting the base substrate 1 to a position where the base substrate 1 is slightly cut, the conductive portions 4a to 4f provided in advance on the base substrate 1 are also divided so as to correspond to the respective nozzles. After that, the printed cable 3 is put on the base substrate 1. Since holes are provided in the print cable 3 at positions corresponding to the piezoelectric elements 2a to 2c, as shown in FIG. 2D, the conductive patterns 6 are located on both sides of the piezoelectric elements 2a to 2c. Then, the conductive pattern 6 of the printed cable 3 and the piezoelectric element 2
a to 2c are electrically connected by soldering, bonding, or the like.

[0010] The ink jet head formed as described above is collectively attached to the diaphragm and assembled into a printer. At the time of printing in the printer, one side of each individual piezoelectric element is a common electrode and the other side is an individual electrode, and a voltage is applied to each individual piezoelectric element from the power supply via the conductive pattern 6 of the print cable 3 and the conductive parts 4a to 4f of the base substrate 1. Is applied. When a voltage is applied, each individual piezoelectric element functions as an actuator for ejecting ink droplets.

As described above, according to this embodiment,
Piezoelectric elements 2a to 2f which are integrally formed as one row of piezoelectric element units on a base substrate 1 on the surface of which conductive portions 4a to 4f and insulating portions 5a to 5e are alternately provided in a strip shape.
A plurality of both ends of 2c are arranged and bonded so as to correspond to different conductive portions, respectively. Each of the piezoelectric elements 2a to 2c is cut into individual piezoelectric elements while being cut into the base substrate 1. Next, the printed cables 3 on which the corresponding conductive patterns 6 are formed and electrically connected to each other are collectively attached to the diaphragm. Therefore, the respective piezoelectric element units corresponding to the respective nozzle rows are collectively attached to the diaphragm, and there is no possibility that the bonding positions of the piezoelectric elements corresponding to the different nozzle rows are shifted to cause a difference in characteristics. . As a result, a desired print result can be obtained in the ink jet head in which each color corresponds to each nozzle row. In this embodiment, the piezoelectric elements are not attached to the diaphragm for each row. Therefore, it is not necessary to take extra mounting margin, and high-density mounting is possible, and furthermore, the size of the device can be reduced. Furthermore, the piezoelectric elements are processed collectively instead of in rows (groove processing)
Then, it can be attached to the diaphragm at once,
Assembly man-hours can be reduced.

Further, if the distance between the conductive portions 4a and 4b is wider than the width of the piezoelectric element 2a, the piezoelectric element 2a can be prevented from riding on the conductive portions 4a and 4b.
The thickness of the adhesive layer below a can be made uniform. As a result, the characteristics can be further improved. The extent of the spread is desirably 20 μm or more in consideration of the positioning accuracy of the pattern. Conversely, the conductive part 4a and the conductive part 4b
May be narrowed by 20 μm or more than the width of the piezoelectric element 2a so that the piezoelectric element 2a is positively placed on the conductive portion. In that case, the piezoelectric element 2a and the conductive portions 4a, 4a
The conduction with the b is more reliable, and the reliability can be improved.

The printed cable 3 is, for example, F
PC (Flexible Printed Cable) and TAB (Ta
Pe Automated Bonding). However, alternatives may be used.

[0014]

As described above, according to the present invention, a plurality of piezoelectric element units corresponding to each nozzle row are formed collectively, so that a plurality of piezoelectric element units can be collectively mounted on the diaphragm. . Therefore, it is possible to prevent the piezoelectric element unit from being displaced in the position where the piezoelectric element unit is attached and to cause a difference in characteristics due to the nozzle row, to reduce the number of manufacturing steps, and to enable high-density mounting, thereby miniaturizing the apparatus. There is an effect that becomes possible.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view for explaining a configuration of an ink jet head according to the present invention.

FIG. 2 is an explanatory diagram for explaining an inkjet head assembling method according to the present invention.

FIG. 3 is a perspective view for explaining a conventional inkjet head assembling method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base board 2a-2c Piezoelectric element 3 Print cable 4a-4f Conductive part 5a-5e Insulating part 6 Conductive pattern

Claims (6)

[Claims] An ink jet head used in an ink jet printer, comprising: a base substrate having a plurality of conductive portions and insulating portions alternately provided in a strip shape on a surface thereof; A plurality of both ends were arranged and bonded so as to correspond to the separate conductive portions, and after each piezoelectric element was cut into individual piezoelectric elements while being cut to the base substrate, a corresponding conductive pattern was formed. An ink jet head, wherein a print cable is covered and the individual piezoelectric elements and the conductive pattern are electrically connected to each other. 2. The ink jet head according to claim 1, wherein a space between the conductive portions on both sides of the piezoelectric element is wider than the width of the piezoelectric element by 20 μm or more. 3. The ink jet head according to claim 1, wherein the distance between the conductive portions on both sides of the piezoelectric element is smaller than the width of the piezoelectric element by 20 μm or more. 4. The ink jet head according to claim 1, wherein the printed cable on which the conductive pattern is formed is a flexible printed cable. 5. The ink jet head according to claim 1, wherein the printed cable on which the conductive pattern is formed is TAB. 6. A piezoelectric element in which a row of heads is integrally formed on a base substrate having a plurality of conductive portions and insulating portions alternately provided on the surface in a strip shape, both ends of which correspond to separate conductive portions, respectively. A plurality of individual piezoelectric elements are cut and cut into individual piezoelectric elements while cutting each piezoelectric element down to the base substrate, and the base substrate is covered with a printed cable on which a corresponding conductive pattern is formed; For assembling an ink jet head for electrically connecting an ink jet head and a conductive pattern.